Default [Q] No storage after ROM instalation

I recently installed hyperdrive on my 16GB GS4 with Safestrap, on my stock slot, it says i have 6 gbs available and 6 Misc. files, but on my Hyperdrive slot i have 13 GB of misc files and 1.6 gb left.. I dont use the stock slot so should I wipe it to get some free space?

Thanks